An Archie comic book depicting a same-sex marriage has been barred from sale in Singapore after a complaint from a member of the public, and the National Library Board (NLB) is reviewing its currently available copies.

Sonny Liew, 39, a graphic novelist based in Singapore, uncovered the restriction after writing to bookseller Kinokuniya on July 10.

When asked, the Media Development Authority (MDA) said it had assessed the comic in March after receiving a complaint and found it breached the guidelines with "its depiction of the same-sex marriage of two characters".

The MDA added: "The Publications Consultative Panel, which comprises a cross-section of (28 members from) Singapore society, was consulted. Its members advised that the theme of the comic was not in line with social norms and is in breach of existing content guidelines."

The MDA said the importing and distribution of publications is largely self-regulated, with book retailers referring to the guidelines on its website.

"MDA reviews public feedback or complaints and takes action on a case-by-case basis if there are breaches of its guidelines," it said.

Checks on the NLB's catalogue on Wednesday night showed it had four copies available for borrowing, from the Ang Mo Kio, Bedok, Cheng San and Yishun libraries. All four copies were on loan.

When asked, the NLB said it had bought the comic book before MDA found it in breach.

"We will be reviewing the book in light of MDA's decision," said a spokesman. It added that the comic was acquired for its adult collection. "NLB takes a broader approach for (this) collection than it does for its children's collection."

The comic book, Archie: The Married Life Book Three, is part of a series that looks at the iconic character's life after he graduates from high school. The book was published in 2013 and depicts the marriage of Kevin Keller, the series' first openly gay character.

In the series' latest issue, which was released in the United States on Wednesday, Archie dies taking a bullet for Kevin, who is now a senator, during an assassination attempt.